viticulture Viticulture (from the Latin word for '' vine'') or winegrowing (wine growing) is the cultivation and harvesting of grapes. It is a branch of the science of horticulture. While the native territory of '' Vitis vinifera'', the common grape vine, ...

, the yield is a measure of the amount of

grape A grape is a fruit, botanically a berry, of the deciduous woody vines of the flowering plant genus '' Vitis''. Grapes are a non- climacteric type of fruit, generally occurring in clusters. The cultivation of grapes began perhaps 8,000 years a ...

s or

wine Wine is an alcoholic drink typically made from fermented grapes. Yeast consumes the sugar in the grapes and converts it to ethanol and carbon dioxide, releasing heat in the process. Different varieties of grapes and strains of yeasts are m ...

that is produced per unit surface of

vineyard A vineyard (; also ) is a plantation of grape-bearing vines, grown mainly for winemaking, but also raisins, table grapes and non-alcoholic grape juice. The science, practice and study of vineyard production is known as viticulture. Vineya ...

, and is therefore a type of crop yield. Two different types of yield measures are commonly used, mass of grapes per vineyard surface, or volume of wine per vineyard surface. The yield is often seen as a quality factor, with lower yields associated with wines with more concentrated flavours, and the maximum allowed yield is therefore regulated for many wine

appellation An appellation is a legally defined and protected geographical indication primarily used to identify where the grapes for a wine were grown, although other types of food often have appellations as well. Restrictions other than geographical boun ...

Units and conversions

In most of

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...

, yield is measured in hectoliters per

hectare The hectare (; SI symbol: ha) is a non-SI metric unit of area equal to a square with 100- metre sides (1 hm2), or 10,000 m2, and is primarily used in the measurement of land. There are 100 hectares in one square kilometre. An acre is ...

, i.e., by the volume of wine. In most of the

New World The term ''New World'' is often used to mean the majority of Earth's Western Hemisphere, specifically the Americas."America." ''The Oxford Companion to the English Language'' (). McArthur, Tom, ed., 1992. New York: Oxford University Press, p. ...

, yield is measured in tonnes per hectare (or short tons per acre in the USA) – i.e. by mass of grapes produced per unit area. Due to differing

winemaking Winemaking or vinification is the production of wine, starting with the selection of the fruit, its fermentation into alcohol, and the bottling of the finished liquid. The history of wine-making stretches over millennia. The science of wine and ...

procedures for different styles of wine, and different properties of different grape varieties, the amount of wine produced from a unit mass of grapes varies. It is therefore not possible to make an exact conversion between these units. Representative figures for the amount of grapes needed for 100 L of wine are 160 kg for

white wine White wine is a wine that is fermented without skin contact. The colour can be straw-yellow, yellow-green, or yellow-gold. It is produced by the alcoholic fermentation of the non-coloured pulp of grapes, which may have a skin of any colour. ...

, 130 kg for red wine, and 140 kg for a mixture of red and white wine. Thus: * for white wine, 100 hl/ha ≈ 16,000 kg/ha (16 t/ha) = 6.5 tons per acre. ** 1 ton per acre = 2470 kg/ha ≈ 15 hl/ha * for red wine, 100 hl/ha ≈ 13,000 kg/ha (13 t/ha) = 5.3 tons per acre. ** 1 ton per acre = 2470 kg/ha ≈ 19 hl/ha * for mixed wine, 100 hl/ha ≈ 14,000 kg/ha (14 t/ha) = 5.7 tons per acre. ** 1 ton per acre = 2470 kg/ha ≈ 17.5 hl/ha

Typical yields

Yields vary greatly between countries, regions and individual vineyards, and can be vintage-dependent. Somewhere around 50 hectoliters per hectare, or 3 tons per acre, is a typical representative figure for many countries and regions.

Yield as an indication of quality

While yield is generally seen as an important quality factor in wine production, views differ on the relative importance of low yields to other aspects of vineyard management. In general, there is consensus that if vines are cropped with a very high amount of grape clusters, a poor wine will result because of slow and insufficient ripening of the grapes, due to an unfavorable leaf to fruit ratio. This is a situation that would typically correspond to yields of, say, 200 hl/ha or more, depending on grape variety and many other factors. Beyond that, there are differing schools of thought. One school of thought, generally subscribed to in France, claims that great red wine is impossible to produce at yields exceeding 50 hl/ha. Another school of thought claims that a yield of 100 hl/ha is possible to combine with high quality, provided that careful

canopy management In viticulture, the canopy of a grapevine includes the parts of the vine visible aboveground - the trunk, cordon, stems, leaves, flowers, and fruit. The canopy plays a key role in light energy capture via photosynthesis, water use as regulated ...

is used. In general, white wine is seen as less sensitive to high yields, and some grape varieties, such as Pinot noir, as particularly sensitive to overcropping. Many examples exist where a vintage-to-vintage variation of yields is in fact positively related with quality, since the low yields can be due to loss of grapes due to adverse conditions such as hail or

grey rot ''Botrytis cinerea'' is a necrotrophic fungus that affects many plant species, although its most notable hosts may be wine grapes. In viticulture, it is commonly known as "botrytis bunch rot"; in horticulture, it is usually called "grey mould" o ...

. For the

Bordeaux Bordeaux ( , ; Gascon oc, Bordèu ; eu, Bordele; it, Bordò; es, Burdeos) is a port city on the river Garonne in the Gironde department, Southwestern France. It is the capital of the Nouvelle-Aquitaine region, as well as the prefect ...

vintages of the 1980s, it is generally recognized that the most abundant harvests also gave the best vintages.

Regulation of yields

In both France and Italy, the maximum allowed yields are regulated in

wine law Wine laws are legislation regulating various aspects of production and sales of wine. The purpose of wine laws includes combating wine fraud, by means of regulated protected designations of origin, labelling practices and classification of wine ...

s, and vary between appellations. In France, the maximum yields are given in the regulations for each ''

appellation d'origine contrôlée An appellation is a legally defined and protected geographical indication primarily used to identify where the grapes for a wine were grown, although other types of food often have appellations as well. Restrictions other than geographical bou ...

'' (AOC). The maximum allowed yield for given AOC in a given vintage is a combination of the base yield of the AOC, as modified by the ''plafond limité de classement'' (PLC), which is percentage set for each vintage. In most vintages, the PLC allows a production around 20 per cent above the base yield.

References

{{portal bar, Drink Viticulture Wine terminology